1. Technical Field of the Invention
The present invention relates to a component mounting apparatus equipped with a tray parts feeder comprising a plurality of stacked trays each accommodating electronic components in rows.
2. Description of Prior Art
Component mounting apparatus of such kind is designed to be flexible in its function of supplying various types of parts and has come into increasing use in recent years. With the widening demand, it has been accordingly desired to improve its performance, and among other things, to reduce the area for installation of the apparatus and to shorten the tact time of mounting operation. Prior art examples of a component mounting apparatus equipped with a tray parts feeder will be described below with reference to FIGS. 8A, 8B and FIGS. 9A, 9B.
FIG. 8A is a block diagram in plan and FIG. 8B is a left side elevation view thereof, showing a component mounting apparatus of so-called xe2x80x9cdirect feed typexe2x80x9d wherein a mounting head takes out parts from a tray and directly mounts them onto a substrate.
In FIGS. 8A, 8B, reference numeral 101 denotes the tray parts feeder, which stocks trays 103 placed on respective tray plates 102. A substrate transfer section denoted 104 is provided for transferring a substrate 105 along guide rails 106. Reference numeral 7 shows some of parts pick-up positions, which can be anywhere on the tray 103, where a mount head (not shown) takes out parts P from tray 103. The movable range of mount head covers the entire area including tray 103 and substrate 105 as indicated in dot-dash lines denoted 8. A tray draw-out driver 9 having a location function using a pulse motor or the like and a position detector is provided for pulling out tray plate 102 from tray parts feeder 101 and locating it at any given position. The surfaces of tray 103 drawn out from tray parts feeder 101 and substrate 105 are positioned at the same elevation so that mount head needs to move only a small distance in upward and downward directions.
The above described component mounting apparatus operates as described below.
Substrate 105 is loaded in along guide rails 106 and located at a predetermined position in substrate transfer section 104. Meanwhile, tray draw-out driver 9 pulls out a tray 103 which is placed at a predetermined position on tray plate 102 from tray parts feeder 101. Mount head takes out parts P aligned in rows on tray 103 and mounts them on substrate 105.
As shown in FIG. 8A, in order to take out all of the parts P on tray 103, there is given a space between tray parts feeder 101 and substrate transfer section 104 by the length A of a longer side of tray 103, and the mount head operates within the range indicated in dot-dash lines 8 covering the area including both of the tray 103 and substrate 105.
In such component mounting apparatus of direct feed type shown in FIGS. 8A, 8B, the moving range 8 of mount head needs to be wide enough to include the area extending the length A. Since the mount head needs to move with a wide stroke, it takes time to pick up parts P from tray 3 and mounts them on substrate 5. Thus the tact time cannot be shortened, and moreover, the apparatus needs a large space for installation.
FIG. 9A is a block diagram in plan and FIG. 9B is a left side elevation view thereof, showing another conventional component mounting apparatus of the type using a shuttle, in which parts are taken out and placed on the shuttle with a transfer unit, and the mount head picks up the parts from the shuttle and mounts them on the substrate.
In FIGS. 9A, 9B, same reference numerals are used to indicate the elements identical to those shown in FIGS. 8A, 8B.
A component transfer device 10 comprises a shuttle 13 for transporting parts P from a position denoted 11 in the vicinity of the tray parts feeder 101 to a pick-up position denoted 12 where the mount head (not shown) picks up parts, and a locatable transfer unit 14 provided in the vicinity of tray parts feeder 101 for taking out parts P from tray 103 and placing them onto shuttle 13 when it is located at position 11. The movable range of mount head is indicated in dot-dash lines denoted 15 and covers the area including the pick-up position 12 of shuttle 13 and the substrate 105. Reference numeral 16 denotes the position of a suction nozzle of the transfer unit 14 where it takes out parts P from tray 103.
Tray 103 is pulled out from tray parts feeder 1 by means of tray draw-out driver 9 and located such that the parts P1 in the first row on tray 103 are positioned just below the suction nozzle position 16 of transfer unit 14. Transfer unit 14 moves in a transverse direction in the figure for taking out parts P1 and placing them onto shuttle 13 which is located at position 11. Shuttle 13 loaded with parts P1 moves to the pick-up position 12 of mount head. When all the parts P1 in the first row on tray 103 have been fed, tray draw-out driver 9 pulls out tray 103 further so that parts P2 in the second row on tray 103 are located below the suction nozzle position 16. Parts are taken out similarly to the parts P1 in the first row. All the parts are thus taken out successively and mounted on substrate 105.
The surfaces of tray 103 drawn out from tray parts feeder 101 and substrate 105 are positioned at the same elevation so that mount head and transfer unit 14 need to move only a small distance in upward and downward directions.
In the component mounting apparatus shown in FIGS. 9A, 9B, although the moving range 15 of mount head is considerably smaller than that 8 of the apparatus shown in FIG. 8A, tray parts feeder 101 and substrate transfer section 104 are distanced from each other by the length B corresponding to the length of a longer side of tray 103 so as to allow all of the parts P to be taken out from tray 103.
The moving stroke of the shuttle 13 extends the length B which is the distance between tray parts feeder 101 and substrate transfer section 104, and it takes time to transport the parts P. Thus the tact time cannot be shortened further and also, the apparatus needs a large space for installation.
The present invention solves these problems by providing a component mounting apparatus in which the space for locating the tray plate and the movable range of the mount head are remarkably reduced so that the tact time of picking up and mounting parts P is shortened and the space for installing the apparatus is diminished.
To accomplish the above object, a component mounting apparatus of the present invention generally comprises a tray parts feeder accommodating stacked trays on which components are stocked in rows, a substrate transfer section having guide rails for transferring a substrate, a mount head for mounting components onto a substrate; and a tray draw-out driver capable of pulling out a tray from the tray parts feeder at any given pitch and positioning same at a predetermined location, wherein a part of the tray drawn out from the tray parts feeder passes under the guide rails of the substrate transfer section.
According to the present invention, pick-up positions of the mount head where it takes out components from tray can be set close to the guide rails for the substrate, since the tray, as it is drawn out by a predetermined pitch, passes under these guide rails. In other words, the moving stroke of the mount head is reduced, and the tact time for taking out components and mounting them onto substrate is accordingly shortened. Moreover, since the space between the tray parts feeder and guide rails for substrate transfer is made smaller, the overall size of the apparatus is reduced and the area for installation thereof is diminished.
It is more preferable if the above apparatus further includes a component transfer device for taking out the components accommodated in rows on the tray and for transporting them to a predetermined pick-up position of the mount head in the vicinity of the substrate, since such transfer device enables the mount head to perform component mounting from the pick-up position onto a substrate and not from the tray, thereby the moving stroke of mount head is further reduced and the tact time is further shortened.
It is more preferable if the above component transfer device includes an elevator provided with a component holder at its distal end, the elevator having a stopper which operates when parts are transferred between the tray and shuttle that are on different elevations, so that the pressure applied to the parts can be maintained same.
If the component transfer device is constructed to be capable of transporting a plurality of components at one time, the time required for transporting components can be further shortened.
The component transfer device should preferably comprise a shuttle for transporting the components to the pick-up position of the mount head and a transfer unit for taking out the components from the tray and transferring them onto the shuttle. With such transfer device, it is possible to transport components to the pick-up position of the mount head during a next set of components are being taken out from the tray.
It is preferable if the trays are accommodated on respective tray plates at a predetermined location thereon, since various sizes of trays can be thereby accommodated in the same apparatus.
While novel features of the invention are set forth in the preceding, the invention, both as to organization and content, can be further understood and appreciated, along with other objects and features thereof, from the following detailed description and examples when taken in conjunction with the attached drawings.